Most people will have a problem with their eyes at some point in their lives. Most eye problems are not serious and do not require the care of a doctor. For example, certain ocular disorders can cause excessive tearing, chronic swelling or inflammation of eyelids, deficient tear production, or abnormal tear composition. Certain eye diseases, however, are serious and can result in blindness if left untreated.
The tears produced by the human eye are composed of three layers: the outer oily layer; the middle watery layer; and the inner mucus layer. Dry eye syndrome (also known as keratoconjunctivitis, keratitis sicca and xerophthalmia) is often used to describe a condition in which not enough tears are produced, or tears with the improper chemical composition are produced. Symptoms of dry eye syndrome vary in different people, but the following are commonly experienced by those whose tear production is inadequate: irritated, scratchy, dry or uncomfortable eyes; redness of the eyes; a burning sensation of the eyes; a feeling of a foreign body in the eye; blurred vision; excessive watering; and eyes that seem to have lost the normal clear glassy luster. Excessive dry eye can damage eye tissue and possibly scar the cornea, thereby impairing vision.
Blepharitis is a chronic or long-term inflammation of the eyelids and eyelashes. Among the most common causes of blepharitis are poor eyelid hygiene, excess oil produced by the glands in the eyelids, bacterial infection, and allergic reaction. There are two ways in which blepharitis may appear. The most common and least severe, seborrheic blepharitis, is often associated with dandruff of the scalp or skin conditions (e.g., acne). It usually appears as greasy flakes or scales around the base of the eyelashes and as a mild redness of the eyelid. Sometimes, it may result in a roughness of the tissue that lines the inside of the eyelids, or in chalazia, which are nodules on the eyelids. Acute infection of the eyelids can result in styes. Ulcerative blepharitis is a less common, but more severe condition that may be characterized by matted, hard crusts around the eyelashes, which leave small sores that may bleed or ooze when removed. There may also be a loss of eyelashes, distortion of the front edges of the eyelids, and chronic tearing. In severe cases, the cornea may also become inflamed.
Epiphora is the term commonly used to describe a watery eye. More specifically, lacrimation describes persistent welling of tears in the eye, and epiphora is when these tears spill over onto the face. Epiphora is caused by overproduction of tears and/or inadequate/blocked drainage. Both lacrimation and epiphora can be associated with interference in vision, and the surrounding skin can become very sore and excoriated from the constant wiping of tears.